The present invention pertains to self-blunting needle devices and, in particular, to holders for blood collection needles.
Conventional blood collection systems are known in the art to comprise a holder, typically in the form of a generally cylindrical shell, that holds a double-ended needle cannula. One end of the needle cannula extends forward from the holder and is used for venipuncture (the xe2x80x9cvenipuncture needlexe2x80x9d) while the other end (the xe2x80x9cfilling needlexe2x80x9d) extends into the holder and is used to puncture the seal cap on a sample fluid collection tube (which, typically, is vacuum-sealed). The device is used by unsheathing the venipuncture needle and effecting venipuncture and then inserting the sealed end of a collection tube into the holder and pushing the seal cap against the boot that covers the tip of the filling needle. The filling needle pierces the boot and the seal cap and blood is drawn into the collection tube. If additional samples are required, the first collection tube is removed and a second collection tube is pushed into the holder in its place. When the last tube is filled, the blood collection needle is withdrawn from the patient""s vein.
Prior art self-blunting blood collection needles have provided a deployable, locking, blunting member to protect the user against inadvertent needle sticks but required the user to engage in an extraneous manipulation of the sample tube in order to deploy the blunting member such as the insertion of the sample tube past a discernible xe2x80x9cstopxe2x80x9d point at which the collection tube is already fully engaged by the filling needle. There is need, therefore, for a self-blunting needle mechanism that does not require manipulation beyond that which is familiar to medical technicians with the use of conventional blood collection needles.
The present invention relates to a needle holder apparatus comprising a shell dimensioned and configured for receiving and holding a sample collection tube therein and for carrying thereon a needle cannula, an actuator movably disposed in the shell for engaging and moving a blunting member longitudinally within the shell and means for moving the actuator between a forward position and a retracted position in response to the insertion and withdrawal of a sample collection tube in the shell.
According to one aspect of the invention, the means for moving the actuator may comprise a transmitter device connected to the shell and being configured to move obliquely in the shell upon insertion of such sample collection tube into the shell. There may also be a linkage between the transmitter device and the actuator to convert the oblique motion of the transmitter device into rearward motion of the actuator when such sample tube is inserted into the apparatus. The apparatus may include a biasing member positioned and configured to urge the actuator toward the forward position.
In one species of the invention, the linkage may comprise a cam and follower engagement between the actuator and the transmitter device. Optionally, there may be a staggered cam and follower engagement between the actuator and the transmitter device.
According to yet another aspect of the invention, the transmitter device may be configured to contact such sample collection tube at a point between the connection to the shell and the linkage to the actuator.
According to yet another aspect of the invention, the transmitter device may extend forwardly in the shell from its point of attachment to the shell.
According to still another embodiment of the invention, the transmitter device may comprise at least two transmitter arms.
According to another aspect of the invention, either of the actuator and the transmitter device may comprise a cam surface.
The apparatus may comprise a biasing member urging the actuator member toward the forward position.
In a particular embodiment, this invention may provide a needle holder apparatus comprising a shell dimensioned and configured for receiving and holding a sample collection tube therein and for carrying thereon a needle cannula, an actuator movably disposed in the shell for engaging and moving a blunting member axially within the shell, a transmitter device connected to the shell and being configured to contact a sample collection tube which may be inserted into the shell and to move obliquely relative to the motion of the sample collection tube, and a positive motion cam engagement between the transmitter device and the actuator to convert the oblique motion of the transmitter device into axial motion of the actuator, to move the actuator axially in the shell in response to the oblique motion of the transmitter device, wherein the apparatus is biased to dispose the actuator in the forward position.
The present invention also provides a blood collection needle comprising a shell dimensioned and configured for receiving and holding a sample collection tube therein, a needle cannula carried on the shell, a blunting member disposed telescopically within the needle cannula for movement between a withdrawn position which disposes the needle in a sharpened configuration and a blunting position which disposes the needle in a blunted configuration, and a mechanism for moving the blunting member to the withdrawn position when a sample collection tube is inserted into the holder and for moving the blunting member to the blunting position when the sample collection tube is withdrawn from the shell.
In a particular embodiment, the mechanism may comprise an actuator movably disposed in the shell, the actuator being secured to the blunting member so that the blunting member can be moved between the blunting position and the withdrawn position by movement of the actuator, a movable transmitter device connected to the shell and being configured for contact with a sample collection tube which may be inserted into the shell and to move obliquely relative to the motion of a sample collection tube in the shell, a biasing member configured to urge the blunting member to the blunting position upon withdrawal of a sample collection tube from the shell, and a linkage between the transmitter device and the actuator to convert the oblique motion of the transmitter device into forward and rearward motion of the actuator, to move the blunting member from the blunting position to the withdrawn position.